Unseeded Vasil Kirkov advanced to his first Grade A quarterfinal by coming from 5-3 down in the final set to beat Lucas Koelle of Brazil 4-6, 7-6(3), 7-5. He faces top seed Yosuke Watanuki of Japan next. Unseeded John McNally, who reached the Orange Bowl quarterfinals in December, ousted No. 10 seed and Banana Bowl finalist Louis Wessels of Germany 7-5, 6-1, his third consecutive straight set win. No. 2 seed Ulises Blanch, who would have played McNally in the quarterfinals, fell to No. 14 seed Duarte Vale of Portugal 6-4, 7-5.

Two American teenagers have advanced to the quarterfinals of the $125,000 +hospitality ATP Challenger in Irving Texas, both getting wins over lucky losers. Wild card Frances Tiafoe defeated Giovanni Lapentti of Ecuador 6-3, 2-6, 6-2 to set up a meeting with defending champion and No. 4 seed Aljaz Bedene of Great Britain. Jared Donaldson, who received entry as an alternate, served for the match three times against former LSU star Michael Venus of New Zealand, finally claiming a 6-4, 6-7(7), 6-3 victory. He will next play 2014 ITF World Junior Champion Andrey Rublev of Russia, who won his first Challenger title two weeks ago in France.

At the $50,000 Challenger in Drummondville, Canada, 16-year-old wild card Denis Shapovalov upset No. 2 seed Austin Krajicek 6-3, 7-5 to reach the quarterfinals. The 2015 US Open boys doubles champion, who won a Futures title in Florida in January, now has his first two Challenger level wins. He is also into the doubles semifinals partnering 18-year-old Tim van Rijthoven of the Netherlands, who also has a one-handed backhand.

In the $100,000 Guadalajara Challenger, Alex Sarkissian picked up a huge win last night, beating top seed and ATP No. 67 Victor Estrella Burgos of the Dominican Republic 6-2, 2-6, 7-5 in the first round. Dennis Novikov has advanced to the quarterfinals with a 6-3, 6-4 win over Eduardo Struvay of Colombia.

The American quarterfinalists at the $10,000 women's tournament in Orlando are top seed Jessica Pegula, No. 2 seed Katerina Stewart, No. 6 seed Sanaz Marand and qualifier Grace Min. Marand and Stewart will play in Friday's quarterfinals.